A drive end block for a rotatable magnetron is described hereafter, which has a simple construction and is easy to maintain.
So-called rotatable magnetrons are known in vacuum coating technology, in which a typically tubular target encloses a magnet configuration, the tubular target being mounted so it is rotatable and being drivable, so that the target material is ablated uniformly. The rotating magnetron is typically fastened in the vacuum chamber of a vacuum coating facility between two end blocks, which are designed so that they allow the rotatable mounting of the tubular target in each case. Different functions are usually assigned to the two end blocks in this case. One of the end blocks is typically implemented as a supply end block for supplying the magnetron with cooling water and electrical power and the other end block is implemented as a drive end block for introducing a torque to generate the rotation of the tubular target.
Known drive end blocks have an electromechanical drive apparatus in the form of an electric motor having gears for this purpose, which introduces the torque via bevel gears, spur gears, or toothed belts, for example. This drive apparatus must be free of potential and is therefore installed insulated in relation to the target and in relation to the vacuum chamber. Therefore, the drive apparatus is installed directly in the drive end block using insulators in known drive end blocks. As a function of the level of the electrical processing voltage, the outlay for the potential separation may be very great, in order that the processing voltage applied to the tubular target is reliably prevented from flashing over onto the drive apparatus or the vacuum chamber.
Inside the vacuum chamber, the torque is typically transmitted via an insulated coupling element from the drive apparatus situated in the interior of the drive end block to the target located in the vacuum chamber. Because the drive end block unifies the functions of introducing rotation, electrical insulation, and the vacuum seal, the components of the drive end block must be manufactured and mounted with great precision.